January 23 2007
GW Pharmaceuticals announced preliminary results of two Phase III studies of Sativex®, its cannabinoid spray medicine, in peripheral neuropathic pain.

The results of the study in patients with neuropathic pain characterized by allodynia show that patients taking Sativex obtain clinically important improvements in their management of pain and quality of sleep. In comparison with placebo, statistically significant improvements were seen for key outcome measures, including a positive result in the primary analysis of patient response, the outcome measure recommended by regulatory authorities.

The results of the study in patients with painful diabetic neuropathy show that patients taking Sativex obtained substantial improvements in their pain, indeed among the highest level of response seen in the published literature. There was an abnormally large placebo response in this study, which means that the data are more difficult to interpret categorically.

Dr Stephen Wright, GW’s R&D Director, said, “Neuropathic pain is one of the most difficult types of chronic pain to treat. These studies focused on particularly high need patients, who were already taking the best available pain treatments, and yet still suffered severe pain. Even in this most difficult to treat population, Sativex has produced improvements over and above current treatments that are highly meaningful to the everyday lives of patients.”

This multi-centre double-blind, randomized, placebo-controlled parallel group study in 297 patients examined the effect of Sativex in patients with painful diabetic neuropathy. Patients in this study were being treated with a range of currently available analgesics, which were maintained during the course of the study.

In this study, patients taking Sativex showed a 30% mean improvement in pain scores, among the highest level of response seen in the published literature. One third of Sativex patients achieved over a 50% improvement in pain.

Sativex is approved and marketed in Canada for the symptomatic relief of central neuropathic pain in MS, and is the subject of an ongoing regulatory submission in Canada for the relief of cancer pain.